Creseis virgula conica [Status Unaccepted]   Eschscholtz,  1829 (Tusk Shell)
Organism information awaits expert curation
Taxonomy
Kingdom:Animalia
Phylum:Mollusca
Class: Gastropoda
Order:Thecosomata
Family:Creseidae

Image copyrights: L. Newman

Description
Size: Maximum shell length is 7 mm.

This forma changes gradually into the formae virgula and clava when its general shape is considered. Most typical is the rounded embryonic shell which does not show rings or any constriction, and the strong curvature (the angle between teleoconch and protoconch is <150°). Only a few growth striae are found above the embryonic shell. The fully-grown shell is colorless, 7 mm long, with an aperture-diameter of about 1 mm (Creseis virgula conica). The anterior part of the shell is straight, only the posterior top is curved dorsally. The incomplete original description makes it difficult to detect exactly the status of this taxon. The names of the two forma are frequently exchanged. The soft parts are characterized by the wing appendages and the short columellar muscle.
The juveniles are characterized by the curve of the shell. The protoconch I is nearly straight, slender and conical with blunt tip. The incision between adult and embryonic shell is faint and at the level of this incision the curvature begins. Growth rate is 0.30 mm per month.

This form is a protandric hermaphrodite.


Synonym (s)

Common Name (s)
Economic Importance and Threats

Ecology

Biogeography


• Andaman Sea INDIA (Record: 05/2000)

Literature Source(s)
  • Bhattacharjee, D (2005) Pteropod preservation profiles in seabed sediments off Middle Andaman Island in Andaman Sea Indian Journal of Marine Sciences CSIR 34(3) 259-266 Available at - http://nopr.niscair.res.in/handle/123456789/1561
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at - http://www.marinespecies.org
  • van der Spoel, S; Newman, LJ and Estep, KW Pelagic molluscs Marine Species Idenification Portal Available at - http://www.species-identification.org/species.php?species_group=pelagic_molluscs&menuentry=colofon

Page last updated on:2012-10-18

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